Title: P1‐305: Greater rate of atrophy in elderly with high versus low Aβ deposition
Abstract: It is still unknown which are the relevant pathological events that lead to brain neurodegeneration in Alzheimer's disease. The dominating “amyloid cascade” hypothesis proposes that excess Aß initiates a cascade of events that result in neuronal death and cognitive decline. There is however no evidence to date that excess Aß accelerates neuronal loss in the early stage of the disease. The present study aims at assessing whether the presence of Aß influences the rate of atrophy in normal elderly. Regions where PiB+ participants exhibited faster atrophy compared to PiB- (up) and where baseline PiB neocortex-to-pons ratio significantly correlated to the annual rate of atrophy (down). Results are superimposed onto a 3D inflated surface view of the average brain of all participants (left) and plots are obtained by averaging the annual rate of atrophy of each individual across all significant voxels (right). Statistical maps are thresholded at T > 2.6 corresponding to a p (uncorrected for multiple comparisons) > 0.005.